Bottom Line:
This new approach to a tracking system was tested for its applicability in a series of field and laboratory tests.BAARA has been tested within fieldwork explorations of Rousettus aegyptiacus during field trips to Dakhla oasis in Egypt.The results illustrate the novel perspective which automated radiotracking opens for the study of spatial behaviour, particularly in addressing topics in the domain of population ecology.

ABSTRACTRadiotracking is an important and often the only possible method to explore specific habits and the behaviour of animals, but it has proven to be very demanding and time-consuming, especially when frequent positioning of a large group is required. Our aim was to address this issue by making the process partially automated, to mitigate the demands and related costs. This paper presents a novel automated tracking system that consists of a network of automated tracking stations deployed within the target area. Each station reads the signals from telemetry transmitters, estimates the bearing and distance of the tagged animals and records their position. The station is capable of tracking a theoretically unlimited number of transmitters on different frequency channels with the period of 5-15 seconds per single channel. An ordinary transmitter that fits within the supported frequency band might be used with BAARA (Biological AutomAted RAdiotracking); an extra option is the use of a custom-programmable transmitter with configurable operational parameters, such as the precise frequency channel or the transmission parameters. This new approach to a tracking system was tested for its applicability in a series of field and laboratory tests. BAARA has been tested within fieldwork explorations of Rousettus aegyptiacus during field trips to Dakhla oasis in Egypt. The results illustrate the novel perspective which automated radiotracking opens for the study of spatial behaviour, particularly in addressing topics in the domain of population ecology.

pone.0116785.g008: Spatial activity pattern of fruit bats.a) Triangulated locations of the representative fruit bat, R. aegyptiacus, tracked for one night during field tests of the BAARA automated radiotracking system. Black dot—roost, large black triangles—automated stations, small triangles—locations (n = 384), solid line—100% minimum convex polygon, elipses—kernel estimations 50% contour lines. Different colours show the level of triangulation: white—no triangulation; grey—by two; and black—by three stations. There are three feeding sites, isolated locations mark the commuting bat. b) Spatial activity pattern of a fruit bat population in Dakhla oasis, Egypt, in different periods of the year as revealed by instrumental record of automated radiotracking. The feeding time is a period with no changes in successive positioning of an individual in a record of single BAARA station, the search time is a period of changing successive positioning. Each sign expresses the sum of the respective two variables in a whole night record of an individual from a single BAARA station.

Mentions:
Finally, the system was deployed in the Dakhla oasis in Egypt during three field trips (winter 2010, spring and summer 2011), where we consecutively tagged R. aegyptiacus in a study area covering 10 × 10 km. Five stations took bearings every 2–10 min, based on the number of simultaneously followed bats. When more stations took a bearing of a particular transmitter, its precise location was calculated by triangulation during the post-processing of data (Fig. 8).

pone.0116785.g008: Spatial activity pattern of fruit bats.a) Triangulated locations of the representative fruit bat, R. aegyptiacus, tracked for one night during field tests of the BAARA automated radiotracking system. Black dot—roost, large black triangles—automated stations, small triangles—locations (n = 384), solid line—100% minimum convex polygon, elipses—kernel estimations 50% contour lines. Different colours show the level of triangulation: white—no triangulation; grey—by two; and black—by three stations. There are three feeding sites, isolated locations mark the commuting bat. b) Spatial activity pattern of a fruit bat population in Dakhla oasis, Egypt, in different periods of the year as revealed by instrumental record of automated radiotracking. The feeding time is a period with no changes in successive positioning of an individual in a record of single BAARA station, the search time is a period of changing successive positioning. Each sign expresses the sum of the respective two variables in a whole night record of an individual from a single BAARA station.

Mentions:
Finally, the system was deployed in the Dakhla oasis in Egypt during three field trips (winter 2010, spring and summer 2011), where we consecutively tagged R. aegyptiacus in a study area covering 10 × 10 km. Five stations took bearings every 2–10 min, based on the number of simultaneously followed bats. When more stations took a bearing of a particular transmitter, its precise location was calculated by triangulation during the post-processing of data (Fig. 8).

Bottom Line:
This new approach to a tracking system was tested for its applicability in a series of field and laboratory tests.BAARA has been tested within fieldwork explorations of Rousettus aegyptiacus during field trips to Dakhla oasis in Egypt.The results illustrate the novel perspective which automated radiotracking opens for the study of spatial behaviour, particularly in addressing topics in the domain of population ecology.

ABSTRACTRadiotracking is an important and often the only possible method to explore specific habits and the behaviour of animals, but it has proven to be very demanding and time-consuming, especially when frequent positioning of a large group is required. Our aim was to address this issue by making the process partially automated, to mitigate the demands and related costs. This paper presents a novel automated tracking system that consists of a network of automated tracking stations deployed within the target area. Each station reads the signals from telemetry transmitters, estimates the bearing and distance of the tagged animals and records their position. The station is capable of tracking a theoretically unlimited number of transmitters on different frequency channels with the period of 5-15 seconds per single channel. An ordinary transmitter that fits within the supported frequency band might be used with BAARA (Biological AutomAted RAdiotracking); an extra option is the use of a custom-programmable transmitter with configurable operational parameters, such as the precise frequency channel or the transmission parameters. This new approach to a tracking system was tested for its applicability in a series of field and laboratory tests. BAARA has been tested within fieldwork explorations of Rousettus aegyptiacus during field trips to Dakhla oasis in Egypt. The results illustrate the novel perspective which automated radiotracking opens for the study of spatial behaviour, particularly in addressing topics in the domain of population ecology.